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364                  PATHOGENIC BACTERIA.

simultaneous inoculation of bacteria not at all related to
anthrax will sometimes recover the animal, as Hiippe
found. Hankin found in the cultures chemical sub-
stances, especially an albuminose, which exerted a pro-
tective influence. Chamberland has shown that pro-
tective inoculation by Pasteur's method has diminished
the death-rate from 10 per cent, for sheep and 5 per
cent, for cattle to about 0.94 per cent, for sheep and 0.34
per cent, for cattle, so that the utility of the method is
scarcely questionable. In 1890, Ogata and Jasuhara
showed that in the convalescents from anthrax among
their experimental animals an antitoxic substance was
present in the blood in such quantities that i : 800 parts
per body-weight of dog's serum containing the antitoxin
would protect a mouse. Similar results have been at-
tained by Marchoux.

Experiments of interest have been performed to show
that the natural immunity enjoyed by many animals can
be destroyed. Behring found that if the alkalinity of the
blood of rats was diminished, they could become affected
with anthrax, and numerous observers have shown that
when anthrax bacilli and unrelated organisms, such as
the erysipelas cocci, Bacillus prodigiosus, and Bacillus
pyocyaneus, are simultaneously introduced into immune
animals, the immunity is destroyed and the animals
succumb to the disease. Frogs have been made to suc-
cumb to the disease by exposure to a temperature of 37°
C. after inoculation. Pasteur destroyed the immunity of
fowls by a cold bath after inoculation.

In the natural order of events anthrax in cattle is
probably the result of the inhalation or ingestion of the
spores of the bacilli from the pasture. At one time
much discussion arose concerning the infection of the
pasture. It was argued that, the bacilli being enclosed
in the tissues of the diseased animals, the infection of
the pasture must be due to the distribution of the germs
from the buried cadaver to all parts of the field, either
through the activity of earth-worms, which ate of the